Hydrolase Activity Research Articles

Ground cover management enhances soil extracellular enzyme activities across Chinese orchards.

The impacts of ground cover management (GCM) on orchard soil properties have been extensively studied. However, the quantitative assessment of soil extracellular enzyme activities (EEAs) in mulch agriculture remains understudied. In this study, we investigated EEAs related to GCM to assess microbial metabolic activity, soil health, and nutrient status, based on 81 studies focusing on orchards in China. Our findings show that GCM significantly increases carbon acquisition (C-acq, 37%), nitrogen acquisition (N-acq, 34%), phosphorus acquisition (P-acq, 26%), and oxidative decomposition (OX, 14%) enzymes compared to continuous clean tillage. A subgroup analysis and a random forest model were conducted to further identify the effects and potential mechanisms through which soil EEAs respond to GCM in orchards under various moderators. The significant changes in EEAs induced by GCM vary with experimental and environmental factors. Tree age, climate conditions, and soil depth are the primary contributors to the variation in soil EEAs. Overall, our results suggest that the implementation of GCM positively affects EEAs, thereby enhancing microbe-mediated soil ecosystem functions and soil fertility. This meta-analysis provides comprehensive evidence of GCM-induced effects on hydrolase and oxidase activity, improving our understanding of the underlying mechanisms by which orchard mulching impacts soil nutrient cycling.

Response of bacterial and fungal composition in tailings to Mn pollution

Microorganisms are crucial for natural remediation of heavy metal pollution in mining areas. The regional survey and process analysis of Mn mine microbes is still limited. We investigated microbial species composition in tailings and adjacent soils of seven typical Mn mining areas in wet mid-subtropical China. The Mn bioavailable content in tailings was 55 times higher than in soils. Compared to soils, the heavy metal pollution in tailings reduced the hydrolase activities and microbial species diversity by 97% and 38%, respectively. The co-occurrence network of bacterial and fungal species in tailings was dominated by symbiosis and synergism, and their network complexity was lower than soils. Linear discriminant analysis of effect size revealed that Ralstonia, Acidisoma, and Talaromyces were the species most stimulated by Mn pollution because their relative and absolute abundance in tailings was much higher than in soils (p < 0.001). These key species defined the co-occurrence networks and affected metabolic pathways of microbial communities. Electrical conductivity and its interaction with Mn bioavailability strongly affected tailings microbial key species. This work identified the key species adapted to extreme Mn pollution in tailings, that can be used by bioremediation and maintenance of ecosystem functions in Mn-contaminated soils.

Impact of porcine brush border membrane enzymes on INFOGEST in vitro digestion model: A step forward to mimic the small intestinal phase

Brush border membrane (BBM) enzymes greatly affect the bioaccessibility and bioavailability of food nutrients. Despite their physiological importance, a step simulating the final stage of intestinal digestion has not yet been included in the harmonized protocols for in vitro digestion, primarily due to the challenges of replicating the dynamics of intestinal degradation. Herein, we propose an advancement toward a more physiologically relevant method, complementing the harmonized static gastric-duodenal digestion INFOGEST model with the missing small intestinal phase. BBM hydrolase activity, incubation time, at pH 7.2 were established to reproduce the small intestinal conditions. Skim milk powder, as a model of protein food, was subjected to the in vitro static digestion. Immediately after the duodenal phase, digesta were supplemented with BBM vesicles purified from pig jejunum. To comply with the dynamic nature of intestinal digestion and balance the spontaneous inactivation of hydrolases, BBM supplements were added every two hours throughout 6 h incubation time. Peptide degradation was monitored at each stage of digestion by amino acid analysis, free α-amino group assay, HPLC, LC-MS/MS. Hydrolysis by BBM peptidases led to a significant increase of free amino acids, reflecting the known level of amino acid adsorption (> 90 %) in humans after eating milk proteins. LC-MS/MS analysis demonstrated that BBM hydrolases erode progressively the peptides released by gastro-duodenal processing up to stable sequence motifs. The approach described is particularly relevant when the endpoint is identifying the peptide sequences that cannot be further hydrolysed by digestive enzymes or to determine the amino acid bio-accessibility.

Paraburkholderia tropica Primes a Multilayered Transcriptional Defense Response to the Nematode Meloidogyne spp. in Tomato

Meloidogyne causes a devastating disease known as root-knot that affects tomatoes and other cash crops worldwide. Conversely, Paraburkholderia tropica has proven beneficial in mitigating the effects of various pathogens in plants. We aimed to unravel the molecular events that underlie the beneficial effects of the bacterium and the detrimental impacts of the nematode when inoculated separately or together in tomato plants. The transcriptional responses induced by P. tropica (TB group (tomato-bacteria group)), Meloidogyne spp. (TN group (tomato-nematode group)) or by the two agents (TBN group (tomato-bacteria-nematode group)) in tomato were assessed by RNA-seq. We implemented a transcript discovery pipeline which allowed the identification of 2283 putative novel transcripts. Differential expression analysis revealed that upregulated transcripts were much more numerous than downregulated ones. At the gene ontology level, the most activated term was ‘hydrolase activity acting on ester bonds’ in all groups. In addition, when both microbes were inoculated together, ‘hydrolase activity acting on O-glycosyl compounds’ was activated. This finding suggests defense responses related to lipid and carbohydrate metabolism, membrane remodeling and signal transduction. Notably, defense genes, transcription factors and protein kinases stood out. Differentially expressed transcripts suggest the activation of a multifaceted plant defense response against the nematode occurred, which was exacerbated by pre-inoculation of P. tropica.

Assessment of the safety and hepatic lipid-lowering effects of Lactobacillus delbrueckii subsp. lactis CKDB001

Probiotics have been shown to provide health benefits for several metabolic diseases, including obesity, type 2 diabetes, and metabolic dysfunction-associated steatotic liver disease (MASLD), by modulating the gut microbiota. In this study, we evaluated the safety and efficacy of Lactobacillus delbrueckii subsp. lactis CKDB001 as a potential therapeutic candidate for the treatment of MASLD. We evaluated antibiotic resistance, hemolytic, gelatinase, and bile salt hydrolase activities, and the production of biogenic amines and D-lactate using in vitro analyses. We found that L. lactis CKDB001 treatment resulted in significant anti-adipogenic properties in the HepG2 cell line, reducing lipid accumulation and improving lipid profiles through mechanisms involving the upregulation of SIRT1 and PPARα, and downregulation of CD36 and ELOVL6. These results suggest that L. lactis CKDB001 is a safe and effective probiotic for managing MASLD. Further in vivo studies and clinical trials are required to validate these effects and fully elucidate their therapeutic potential and safety profiles.

Systematic Optimization of Activity-Based Protein Profiling for Identification of Polysorbate-Degradative Enzymes in Biotherapeutic Drug Substance down to 10 ppb.

The identification and control of high-risk host cell proteins (HCPs) in biotherapeutics development are crucial for ensuring product quality and shelf life. Specifically, HCPs with hydrolase activity can cause the degradation of excipient polysorbates (PS), leading to a decrease in the shelf life of the drug product. In this study, we systematically optimized every step of an activity-based protein profiling (ABPP) workflow to identify trace amounts of active polysorbate-degradative enzymes (PSDEs) in biotherapeutic process intermediates. Evaluation of various parameters during sample preparation pinpointed the optimal pH level and fluorophosphonate (FP)-biotin concentration. Moreover, the combined use of a short liquid chromatography gradient and the fast-scanning parallel accumulation-serial fragmentation (PASEF) methodology increased sample throughput without compromising identification coverage. Tuning the trapped ion mobility spectrometry (TIMS) parameters further enhanced sensitivity. In addition, we evaluated various data acquisition modes, including PASEF combined with data-dependent acquisition (DDA PASEF), data-independent acquisition (diaPASEF), or parallel reaction monitoring (prm-PASEF). By employing the newly optimized ABPP workflow, we successfully identified PSDEs at a concentration as low as 10 ppb in a drug substance sample. Finally, the new workflow enabled us to detect a PSDE that could not be detected with the original workflow during a PS degradation root-cause investigation.

A Combined Impact of Low-Voltage Electrostatic Field and Essential Oil on the Postharvest Properties of Chili Pepper: Insights into Related Molecular Mechanisms.

This research is intended to ascertain the impact of low-voltage electrostatic field (LVEF) together with chili pepper leaf essential oil (CLEO) on the storage quality of chili pepper. Four groups of samples were investigated, namely, control (CK), CLEO, LVEF, and CLEO + LVEF. Chili pepper from the CLEO + LVEF group reduced the weight loss and malondialdehyde content but improved the ascorbic acid contents, antioxidant potential, firmness, and color attributes. CLEO and LVEF could maintain the integral structure and stability of the cell wall by suppressing the activities of hydrolases of pectin, cellulose, and hemicellulose. The positive role of CLEO + LVEF on the color quality was explained by the significantly higher chlorophyll content and lower activities of chlorophyllase, pheophytinase, and Mg-dechelatase compared to the CK group. Taken together, all data provide supporting evidence for a synergistic effect of CLEO and LVEF on the enhancement of postharvest traits of chili peppers.

Mycoplasma bovis 5'-nucleotidase is a virulence factor conferring mammary fitness in bovine mastitis.

Nucleases and 5' nucleotidase (5'-NT) play essential roles in cell biology and are often associated with bacterial virulence. In Mycoplasma spp., which have limited metabolic capacities and rely on nutrient availability, these enzymes are of significant importance for nucleotide salvage. This study explores the potential role of 2 membrane-associated lipoproteins, the major nuclease MnuA and 5'-NT, in Mycoplasma bovis mastitis. Mutants deficient in MnuA (mnuA::Tn) and in 5'-NT (0690::Tn) were identified through genome-wide transposon mutagenesis of M. bovis PG45 type strain and their fitness and virulence were assessed both in vitro, in axenic medium, and in vivo, using murine and cow mastitis models. The mnuA::Tn mutant demonstrated reduced nuclease activity, while 0690::Tn exhibited slow log-phase growth and impaired hydrolase activity towards nucleotides as well as deoxynucleotides (dAMP and dGMP). In comparison to the parent strain, the 0690::Tn mutant displayed markedly reduced fitness, as evidenced by a significant decrease or even absence in post-challenge mycoplasma counts in murine and cow mammary tissues, respectively. Moreover, the 0690::Tn mutant failed to induce mastitis in both experimental models. Conversely, the mnuA::Tn mutant induced inflammation in murine mammary glands, characterized by neutrophil infiltration and increased expression of major inflammatory genes. In cows, the mnuA::Tn was able to cause an increase in somatic cell counts in a manner comparable to the wild type, recruit neutrophils, and induce mastitis. Collectively, these findings provide complementary insights, revealing that disruption of 5'-NT significantly attenuated M. bovis pathogenicity, whereas a MnuA-deficient mutant retained the ability to cause mastitis.

Functional identification of soluble uric acid as an endogenous inhibitor of CD38.

Excessive elevation or reduction of soluble uric acid (sUA) levels has been linked to some of pathological states, raising another subject that sUA at physiological levels may be essential for the maintenance of health. Yet, the fundamental physiological functions and molecular targets of sUA remain largely unknown. Using enzyme assays and in vitro and in vivo metabolic assays, we demonstrate that sUA directly inhibits the hydrolase and cyclase activities of CD38 via a reversible non-competitive mechanism, thereby limiting nicotinamide adenine dinucleotide (NAD+) degradation. CD38 inhibition is restricted to sUA in purine metabolism, and a structural comparison using methyl analogs of sUA such as caffeine metabolites shows that 1,3-dihydroimidazol-2-one is the main functional group. Moreover, sUA at physiological levels prevents crude lipopolysaccharide (cLPS)-induced systemic inflammation and monosodium urate (MSU) crystal-induced peritonitis in mice by interacting with CD38. Together, this study unveils an unexpected physiological role for sUA in controlling NAD+ availability and innate immunity through CD38 inhibition, providing a new perspective on sUA homeostasis and purine metabolism.

Functional identification of soluble uric acid as an endogenous inhibitor of CD38

Excessive elevation or reduction of soluble uric acid (sUA) levels has been linked to some of pathological states, raising another subject that sUA at physiological levels may be essential for the maintenance of health. Yet, the fundamental physiological functions and molecular targets of sUA remain largely unknown. Using enzyme assays and in vitro and in vivo metabolic assays, we demonstrate that sUA directly inhibits the hydrolase and cyclase activities of CD38 via a reversible non-competitive mechanism, thereby limiting nicotinamide adenine dinucleotide (NAD+) degradation. CD38 inhibition is restricted to sUA in purine metabolism, and a structural comparison using methyl analogs of sUA such as caffeine metabolites shows that 1,3-dihydroimidazol-2-one is the main functional group. Moreover, sUA at physiological levels prevents crude lipopolysaccharide (cLPS)-induced systemic inflammation and monosodium urate (MSU) crystal-induced peritonitis in mice by interacting with CD38. Together, this study unveils an unexpected physiological role for sUA in controlling NAD+ availability and innate immunity through CD38 inhibition, providing a new perspective on sUA homeostasis and purine metabolism.

Pressure-tolerant survival mechanism of Schizophyllum commune 20R-7-F01 isolated from deep sediments 2 kilometers below the seafloor

In anaerobic high hydrostatic pressure (HHP) sedimentary environments below the seafloor, fungi are found to dominate the eukaryotic communities, playing crucial ecological roles. However, the specific mechanisms by which fungi adapt to anaerobic HHP environments remain unclear. In this study, we investigated Schizophyllum commune 20R-7-F01 isolated from coal-bearing sediments at a depth of 2 km below the seafloor. By assessing the cell viability, biomass, and cell wall thickness changes of strain 20-7-1 under different HHP conditions, we observed that, compared to 0.1 MPa, strain 20-7-1 exhibited slower growth rates and decreased cell viability at 15 MPa and 35 MPa, yet demonstrated significant pressure tolerance. Transcriptomic and metabolomic analyses revealed that this strain activated the carbohydrate metabolic process to simultaneously utilize ethanol and lactic acid fermentation pathway. Additionally, it activates the oxidoreductase activity and hydrolase activity pathways to detoxify intracellular reactive oxygen species (ROS). Activation of the metal ion binding pathway increases the proportion of unsaturated fatty acids in the cell membrane, while instigation of the integral component of membrane pathway maintains cell wall structural stability. Furthermore, activation of the DNA repair pathway repairs DNA damage, demonstrating its comprehensive adaptive mechanisms against the HHP stress. These research findings deepen our understanding of fungal survival strategies and adaptation mechanisms in extreme environments, laying the groundwork for further exploration of their roles in cycling of carbon, nitrogen, sulfur, and other elements in the deep biosphere.

Lactobacillus johnsonii CCFM1376 improves hypercholesterolemia in mice by regulating the composition of bile acids

Aim: Strains with high bile salt hydrolase (BSH) activity have the potential to regulate cholesterol metabolism. This study aimed to assess the alleviating effect of Lactobacillus johnsonii (L. johnsonii ) CCFM1376, a strain with high BSH activity, on mice with hypercholesterolemia and explore the mechanism of its effect through the modulation of bile acid metabolism. Methods: The BSH activity was measured using the ninhydrin method. C57BL/6J mice were given a high-cholesterol diet to induce hypercholesterolemia with simultaneous gavage of L. johnsonii CCFM1376 for 8 weeks. The biochemical parameters in the serum and liver of hypercholesterolemic mice were measured to assess the alleviating effect of L. johnsonii CCFM1376 on hypercholesterolemia. Bile acid content in the mouse liver, serum, distal ileum contents, and feces was determined using liquid chromatograph mass spectrometer (LC-MS). RNA was extracted from mouse ileum and liver, and the expression levels of relative genes implicated in bile acid metabolism were measured by quantitative real-time PCR (qPCR). Results: Compared to the model group, the group treated with L. johnsonii CCFM1376 exhibited significantly reduced levels of serum total cholesterol (TC) and low-density lipoprotein cholesterol (LDL-C), along with a significant increase in high density lipoproteins cholesterol (HDL-C) level. Moreover, hepatic levels of TC and LDL-C in the CCFM1376 group also decreased significantly. Furthermore, the content and amount of unconjugated bile acids in the hepatic-enteric circulation of the L. johnsonii CCFM1376 group significantly increased, and the total bile acid content in the feces also significantly increased. In the L. johnsonii CCFM1376 group, the relative expression levels of ileal farnesoid X receptor (FXR) and fibroblast growth factor 15 (FGF15) were downregulated, while the relative expression level of CYP7A1 was upregulated. Conclusion: These results indicated L. johnsonii CCFM1376 improves hypercholesterolemia in mice by regulating the composition of bile acids. This provides a reference for probiotic strategy to regulate cholesterol metabolism.

PCR Based Technique for Identification of Bile Salt Hydrolase Positive Lactobacilli

In the burgeoning landscape of probiotic research, the intricate interplay between the gut microbiota and host health has underscored the significance of specific enzymatic activities, notably bile salt hydrolase (BSH) produced by Lactobacilli. Harnessing the potential health benefits associated with BSH activity necessitates a meticulous identification strategy. In response, this study introduces a sophisticated PCR-based technique tailored for the rapid and precise discrimination of lactobacilli strains boasting BSH enzymatic prowess. This PCR-based approach offers a valuable tool for researchers and industry professionals involved in the selection and characterization of probiotic strains with bile salt hydrolase activity. Its speed, accuracy, and adaptability make it a promising method for large-scale screenings and applications in diverse fields, ranging from food science to the development of probiotic supplements aimed at enhancing human health through the modulation of bile acid metabolism. robiotic supplementation, where the modulation of bile acid metabolism holds promise for promoting human health and well-being.

Impact of Flooding on Lands with Emerging Contaminants on the Quality of Receiving Water Bodies

Among crucial factors that control flooding events are extreme climate, urban growth, and mismanagement. Islands in the Nile River have experienced successive cycles of flooding and drying due to recent rainy years in the Nile Basin countries. This paper focuses on the impact of floods on the amounts of ammonium-N released, total concentrations of heavy metals, enzyme activities, and microbial biomass (C and N) in flood soils of 11 Nile River islands. Field moist soils and their airdried counterparts were collected from the outskirts of the island and incubated for 15 days at 30 °C to be analyzed. Results reflected that the amounts of released NH4-N were higher in airdried than in wet soils. The average hydrolysis rates of the studied six enzyme substrates were correlated significantly with organic C, organic N, microbial bio-mass C and N in the field moist soils. The highest correlation coefficients (r) were with rates of hydrolysis of substrates of asparaginase, amidase, and β-glycosaminidase. A significant intercorrelation between rates of hydrolysis of the six studied enzyme substrates and r values which range from 0.81 to 0.98. At 10 mmol kg−1 soil, Co+2, Cd+2, Pb+2, Cu+2, Cr+3, and Ni+2 inhibited the release of NH4-N. Arginine hydrolysis was inhibited by the six heavy metals at 5 mmol kg−1 soil; the most effective inhibitors were Pb+2, Ni+2, and Cr+3. Due to the complex soil enzymatic and organic nitrogen hydrolase activities that occur during floods, fertile fields on the Nile River islands should not be fertilized before the summer flood seasons, which will prevent contamination of the Nile River water and loss of its island soil fertility.

Selective diesterase-like activity of bioinspired FeIIINiII and FeIIIZnII complexes and their 3-aminopropyl silica composites: A homo- and heterogeneous catalytic study

In this study, the preparation and characterization of two new mixed-valence heterodinuclear complexes [FeIIINiII(BPPAMFF)(μ-OAc)2(H2O)]ClO4 (1) and [FeIIIZnII(BPPAMFF)(μ-OAc)2(H2O)]ClO4 (2) with the bioinspired ligand 2-[(N-benzyl-N-2-pyridylmethylamine)]-4-methyl-6-[N-(2-pyridylmethyl)aminomethyl)])-4-methyl-6-formylphenol (H2BPPAMFF) are reported. These compounds were immobilized in 3-aminopropyl silica (APS) to afford composites APS-1 and APS-2 successfully. The aldehyde-containing ligand provided a reactive functional group, which could serve as a cross-linking group to bind the complexes to the directly amino-modified SiO2 surface. The complexes’ chemical integrity on the APS inorganic platform were probed by spectroscopical techniques, such as FTIR, UV–Vis and EPR. Potentiometric and spectrophotometric titrations allowed the chemical species present in solution to be rationalized, and identified which of them were potentially active in the hydrolytic cleavage of phosphodiester 2,4-BDNPP. Kinetic studies showed that FeIIINiII species (1 and APS-1) presented higher catalytic efficiency (E = kcat/KM) than FeIIIZnII species (2 and APS-2). Catalytic mechanisms were proposed based on a series of kinetic experiments, in which all the catalysts tested behaved as selective phosphodiesterases. In addition, it was also demonstrated that the hydrolase activity of the immobilized catalytic centers, APS-1 and APS-2, was better than the homogeneous processes, where second coordination sphere effects may be involved in directing and stabilizing the transition state.

Characterization of Four Carboxylesterases Involved in Detoxification of β-Cypermethrin, λ-Cyhalothrin, and Malathion in Helicoverpa armigera.

Helicoverpa armigera Hübner (Lepidoptera: Noctuidae) is a globally devastating pest and has evolved with varying levels of resistance to a broader spectrum of insecticides. CarEs are major enzymes involved in insecticide detoxification and metabolic resistance. Four CarE genes were identified and cloned from H. armigera, and the expression pattern analyses indicated that they were predominantly expressed in the detoxifying tissues and larval feeding periods. The insecticide inductive assays further suggested that these CarE genes with expressions were significantly upregulated after beta-cypermethrin, lambda-cyhalothrin, malathion, and chlorpyrifos exposures. The purified recombinant proteins of both CarE016B and CarE016C by bacterial expression exhibited significantly higher catalytic efficiency toward α-naphthyl acetate and also showed relatively stronger binding with both β-cypermethrin and λ-cyhalothrin compared to the CarE006C and CarE015A. In vitro metabolism assay with HPLC suggests that CarE016B and CarE016C have the ability to metabolize β-cypermethrin, λ-cyhalothrin, and malathion with varying hydrolase activities. GC-MS/MS analysis identified 3-phenoxybenzaldehyde (3-PBAld) as the metabolite of both β-cypermethrin and λ-cyhalothrin. Homology modeling and molecular docking analyses further indicate that these three types of insecticides could be anchored into the active pocket of both CarEs. Collectively, these results demonstrate that both CarE016B and CarE016C play a critical role in the detoxification of pyrethroid and organophosphate insecticides in H. armigera. This study provides the foundations for a comprehensive understanding of the role of the CarEs family in insecticide detoxification and resistance in H. armigera.

Symbiotic probiotic communities with multiple targets successfully combat obesity in high-fat-diet-fed mice

ABSTRACT Probiotics hold great potential for treating metabolic diseases such as obesity. Given the complex and multifactorial nature of these diseases, research on probiotic combination with multiple targets has become popular. Here, we choose four obesity-related targets to perform high-throughput screening, including pancreatic lipase activity, bile salt hydrolase activity, glucagon-like peptide-1 secretion and adipocyte differentiation. Then, we obtained 649 multi-strain combinations with the requirement that each must cover all these targets in principle. After in vitro co-culture and in vivo co-colonization experiments, only four (<0.7%) combinations were selected as symbiotic probiotic communities (SPCs). Next, genome-scale metabolic model analysis revealed that these SPCs showed lower metabolic resource overlap and higher metabolic interaction potential involving amino acid metabolism (Ammonium, L−Lysine, etc.) and energy metabolism (Phosphate, etc.). Further animal experiments demonstrated that all SPCs exhibited a good safety profile and excellent effects in improving obesity and associated glucose metabolism disruptions and depression-like behaviors in high-fat-diet-fed mice. This anti-obesity improvement was achieved through reduced cholesterol level, fat accumulation and inhibited adipocyte differentiation. Taken together, our study provides a new perspective for designing multi-strain combinations, which may facilitate greater therapeutic effect on obesity and other complex diseases in the future.

Secretory Proteins Are Involved in the Parasitism of Melon by Phelipanche aegyptiaca During the Attachment Stage.

Parasitic plants represent a significant challenge in global agriculture, with Broomrape (Orobanche/Phelipanche spp.) being a notable example of a holoparasitic species that targets the roots of host plants. This study employed comparative transcriptomics to investigate the mechanisms underlying the parasitism of P. aegyptiaca on melon, focusing on both resistant and susceptible interactions. The findings indicate that the critical phase of P. aegyptiaca parasitism occurs during the post-attachment stage. It is suggested that peptidases may play a role in the development of invasive cells, while cell wall-degrading enzymes (CWDEs) are likely involved in cell wall modification and degradation, and transferases, elicitors, and effectors may play a role in immune regulation. In this study, 25 tobacco rattle virus (TRV) recombinant vectors were successfully constructed and functionally validated using a host-induced gene silencing assay to explore the functions of candidate-secreted effector proteins. The results revealed that silencing Cluster-107894.0, Cluster-11592.0, and Cluster-12482.0 significantly decreased the parasitism rate of P. aegyptiaca on Nicotiana benthamiana. Notably, Cluster-107849.0 encodes a cellulase with hydrolase activity, Cluster-11592.0 encodes a periodic-dependent kinase inhibitor with phosphoprotein activity, and Cluster-12482.0 encodes a glucan 1,3-β-glucosidase with hydrolase activity. These findings potentially offer a novel theoretical framework and justification for understanding host-parasite plant interactions, and suggest new avenues for developing crop varieties resistant to parasitic infestation.

Aerobic exercise alleviates statin-induced PCSK9 upregulation by increasing epoxyeicosatrienoic acid levels through the FoxO3a-Sirt6 axis

BackgroundStatins are the cornerstone of low-density lipoprotein cholesterol (LDL-C)-lowering therapy; however, the therapeutic efficacy of statins in countering atherosclerotic cardiovascular disease (ASCVD) is compromised by the concurrent elevation of proprotein convertase subtilisin/kexin type 9 (PCSK9), a pivotal molecule that increases LDL-C levels. Aerobic exercise lowers PCSK9 levels, but the underlying mechanism remains unclear. Therefore, we investigated how aerobic exercise can ameliorate statin-induced increases in PCSK9 levels. MethodsThree-week-old male American Institute of Cancer Research (ICR) mice were fed a high-fat-cholesterol diet (HFD) for 12 weeks and then administered atorvastatin alone or atorvastatin combined with aerobic exercise (Statin+Ex). Moreover, a total of 165 participants with stable coronary heart disease (CHD) enrolled at the inpatient and outpatient departments of the Second Xiangya Hospital of Central South University from January 2018 to July 2020 were randomized into the Statin group (male/female = 51/33) and Statin+Ex group (male/female = 52/29). Patients in the Statin+Ex group underwent treadmill exercise of 45–60 min/day for 7 days. ResultsAerobic exercise effectively alleviated statin-induced PCSK9 upregulation in human patients with CHD and hypercholesterolemic ICR mice (all p < 0.05). Mechanistically, our findings revealed that aerobic exercise induced elevated epoxyeicosatrienoic acids (EETs) plasma levels while concurrently reducing the activity of soluble epoxide hydrolase (sEH) (all p < 0.05), an enzyme responsible for EETs degradation. Further, EETs significantly suppressed PCSK9 expression, subsequently reducing the LDL-C levels (all p < 0.05); this effect was mediated via the activation of the Forkhead box O3a-Silent mating type information regulation 2 homolog 6 (FoxO3a-Sirt6) axis, with no impact on the Sterol Regulatory Element Binding Protein 2 and 3-hydroxy-3-methylglutaryl-CoA reductase (SREBP2-HMGCR) pathway. ConclusionOur study sheds light on the paradigm of “Exercise is Medicine”, providing evidence to support the use of statins combined with exercise in reducing LDL-C levels, and unveils potential avenues for clinical applications of sEH inhibitors, presenting novel prospects for therapeutic interventions in ASCVD.

Isolation and characterization of Bifidobacterium spp. From breast milk with different human milk oligosaccharides utilization and anti-inflammatory capacity

Breast milk is the best source of nutrition for infants. Human milk oligosaccharides (HMOs) and the corresponding HMOs-consuming Bifidobacterium positively influence infant health. This study aims to isolate and characterize Bifidobacterium from breast milk of healthy Chinese mothers, identifying the most efficacious strains for inclusion in simulated maternal milk formulas. Nine Bifidobacterium strains (two of B. breve and seven of B. infantis) were isolated, exhibiting a broad spectrum of probiotic potential. This included tolerance to simulated infant gastrointestinal conditions, notable adhesion, antibacterial, antioxidant activities, and HMOs utilization ability. Lacto-N-Tetraose (LNT) is preferred in early growth among Bifidobacterium isolates. B. breve showed a preference for LNT, whereas B. infantis showed a preference for fucosylated HMOs, and displayed reduced utilization of sialylated HMOs. They also exhibited robust safety profiles, including no hemolytic activity, an appropriate D/L lactate-producing ratio, and non-toxicity in an acute oral toxicity assay on mice. It is noteworthy that B. breve N-90, O-147, B. infantis O-161 and R-1 exhibited anti-inflammatory effects in LPS-induced RAW 264.7 cells. Specifically, a notable reduction in TNF-α levels was observed in pre-treatment, while a decrease in IL-1β and IL-6 levels in co-treatment. B. breve N-90 and B. infantis R-1 were identified finally as promising probiotic candidates. Their whole-genome sequencing analysis confirmed presence of functional genes associated with gastrointestinal colonization, antioxidation, and glycoside hydrolase activity on HMOs. The annotation for antibiotic resistance and virulence genes concurred with phenotypes, further validating the safety. Breast milk is a good source for Bifidobacteria isolation, while Bifidobacteria utilize HMOs in a strain-dependent manner. The two selected strains, B. breve N-90 and B. infantis R-1, are potential candidates for inclusion in simulated maternal milk formulas and deserved further in vivo investigation for their health-promoting effects.